7. PROJECT SUMMARY/ABSTRACT There are a myriad of new HIV pre-exposure prophylaxis (PrEP) drug formulations and delivery modalities under clinical development, and it is expected that a range of biomedical HIV prevention options will soon be available. To enable these options to have maximum public health impact there is an urgent need to create biobehavioral infrastructure (i.e., empirically validated knowledge, guidelines, and tools) that will: a) allow the integration of these new options into existing PrEP delivery systems; b) support adherence and retention in an emerging HIV prevention service system; and c) promote health equity by ensuring that new prevention options expand HIV prevention coverage to highest priority populations. However, limited research exists that integrates lessons from existing implementation efforts for oral PrEP and develops data-driven tools that can be used by research and clinical practice to accelerate diffusion of proven prevention strategies. In response to that need, the specific aims of this project are to: (1) Synthesize intervention components of PrEP service delivery models in seven federally designated Ending the HIV Epidemic (EtHE) hotspot counties across the US, representing diverse geographical contexts, patient populations, and delivery settings; (2) Operationalize a set of PrEP service delivery process and outcome metrics than can be used to assess fidelity to service delivery models for daily oral PrEP and emerging modalities and measure progress toward enhancing biomedical prevention uptake, persistence, and equitable coverage; and (3) Define universal and modality- specific pre-implementation and implementation activities necessary for settings to integrate emerging prevention options into clinical practice. This project builds on the past work of the investigative team in oral PrEP demonstration and implementation projects, development/testing of novel prevention modalities, and dissemination of evidence-based implementation tools for clinical practice. To accomplish our aims, we will apply two seminal theoretical models from the implementation science literature, and collaborate with seven clinical partners in seven EtHE hotspots across the US, as well as a CDC-funded Capacity Building Assistance (CBA) provider who delivers PrEP training and technical assistance to sites across the country. The knowledge generated by this project will not only advance the field of implementation science, but also create tangible tools that can help clinics, heath systems, and policy decision makers improve PrEP implementation outcomes at a population level. This project has the potential to make a significant and sustained impact on the quality of future implementation efforts, and the speed with which new modalities are effectively disseminated to highest priority populations.